http://www.jrsoftware.org/isinfo.php
Inno Setup is free and has a near-Pascal syntax. It is made in Delphi. You don't have to care about that, but I have to say it nonetheless, as Delphi is the language I use, and is not made by Microsoft

Here is an example file, which remove all .rgn file and replace them by another set. Just copy and paste the commands, it should satisfy 95% of your need.
http://www.mediafire.com/?exdkwuebwp7
And here is the look of the Inno script, for whose interested.
